Monoazo dyestuffs



United States Patent MONOAZO DYESTUFFS Edgar Enders, Leverkusen-Bayerwerk, Germany, assignor to Farbenfabriken Bayer Aktiengesellschaft, Leverkusen, Germany, a corporation of Germany No Drawing. Application September 20, 1955 Serial No. 535,514

Claims priority, application Germany September 28, 1954 4 Claims. (Cl. 260-146) The present invention relates to monoazo dyestufis, their metal complex compounds and a process for their manufacture; more particularly it relates to monoazo dye stufls of the following general formula:

wherein R R and R mean hydrogen or non-ionic substituents, and the chromium and cobalt complexes of said dyestufls.

It is an object of the present invention to provide a new process for the manufacture of metal-containing monoazo dyestuffs. It is a further object to provide new chromium and cobalt-containing monoazo dyestuffs with good fastness properties.

The new o-hydroxy-o-amino monoazo dyestuffs according to the invention can be obtained by coupling diazotized 1-amino-Z-hydroxy-benzenes, free from sulfonic and carboxylic acid groups which may bear nonionic substituents, with coupling components of the following general formula:

ro-benzene-4-sulfonamide, 1-amino-2-hydroxy-5-methyl-, benz'ene-4-sulfonamide, 1-amino2-hydroxybenzene-5-al kylsulfones, l-amino-Z-hydroxy-benzene-4-alkylsulfones. Finally may be used aminobenzenes which carry in ortho-position to the amino group a substituent capable Patented Mar. 31, 1959 2 ample, '1-amino-2,S-dimethoxy-benzene and l-amino-Z- methoxy-S-nitrobenzene.

Suitable coupling components are, for example, 2- phenyI-S-aminobenztriazole, 2-phenyl-5-amino-6-methylbenztriazole, 2-phenyl-5-amino-6-methoxy-benztriazole, 2-phenyl-5-amino-6-chlorobenztriazole, 2-(3'-sulfamidophenyl -5-aminobenztriazole, 2- (2'-methoxyphenyl -5- aminobenztriazole, 2-(2'-chlorophenyl)-5-aminobenztriazole, 2-(2'-methoxy-5-sulfomonomethylamido-phenyl)- 5 amino-benztriazole, 2 (2 chlorophenyl) 5 amino- 6-methylbenztriazole, 2 (3' methylsulfonylphenyl) 5- aminobenztriazole, 2 (2 nitrophenyl) 5 aminobenztriazole.

The coupling of the diazotised 1-amino-2-hydroxybenzenes with the 2-aryl-5-aminobenztriazoles may be eifected in usual manner in neutral or weakly acid aqueous solution or suspension, expediently with the addition of dispersive substances or with water-miscible organic solvents.

The conversion of the dyestuffs thus obtained into their chromium or cobalt complexes can be carried out according to known methods, for example, by heating'them with trivalent chromium salts in organic solvents at elevated temperatures or by converting them with bi-valent cobalt salts in neutral or alkaline solutions or suspen- 810118.

The new metal complex monoazo dyestulfs thus obtainable arereadily soluble in water and may be used for dyeing wool, silk, polyamide fibres and polyurethane fibres. They dye these materials from a neutral or weakly acid bath in level brown to green shades very fast to washing, milling, carbonizing, decatizing and to The following examples illustrate the invention without, however, limiting it thereto; the parts by weight and by volume stand in the ratio of gram to milliliter.

Example 1 27 parts by weight of 1-amino-2-hydroxybenzene-5- sulfonic acid amide are diazotized in 150 parts by volume of water and 25 parts by volume of concentrated hydro chloric acid with 10 parts by weight of sodium nitrite in 30 parts by volume of water, and the suspension of the diazo compound is combined with a finely dispersed suspension of 30 parts by weight of Z-phenyI-S-amino benztriazole in 200 parts by volume of water. Subsequently, the mixture is adjusted to a pH-value of 6 by slowly adding a soda solution, and the coupling is completed with stirring at 40-50" C. The mixture is heated to 70-80" C. and the dyestufl is filtered ofi. The dyestuii is hot dissolved by addition of 30 parts by volume of a 40% caustic soda solution in 1,000 parts by volume of water, and filtered off, and an ammoniacal solution of 19 parts by Weight of crystalline cobalt chloride is introduced into the filtrate drop by drop. The metallisation is complete after a short time; the formed cobalt complex of being converted into the hydroxy group as, for ex of the dyestufi corresponding to the formula OH HaN O2.NH|

is completely separated by addition of common salt, filtered oli and dried. It is a dark powder which dissolves in hot water with a violet-brown shade and dyes wool 3 in level dark-brown shades very fast to washing, milling, carbonizing, decatizing and to light.

By using, instead of the above-mentioned diazo component, a corresponding quantity of 1-amino-2-hydroxybenzene-S-sulfonic acid methylamide, I-amino-Z-hydroxybenzene-S-methylsulfone or 1-amino-Z-hydroxybenzene-S- ethylsulfone, dyestuffs of similar properties are obtained.

By using, instead of the above-indicated coupling components a corresponding quantity of 2-phenyl-5-amino 6-rnethylbenztriazole, a similar dyestutf is obtained.

Example 2 27 parts by weight of 1-amino-2-hydroxybenzene-4- sulfonic acid amide are diazotized in 150 parts by volume of water and 25 parts by volume of concentrated hydrochloric acid with 10 parts by weight of sodium nitrite in 30 parts by volume of water, and the suspension of the diazo compound is combined with a suspension of 30 parts by weight of 2-phenyl-5-aminobenztriazole in 150 parts by volume of formamide. The coupling is completed by adding parts by weight of crystalline sodium acetate and by slightly heating the mixture. The mixture is then stirred with 500 parts by volume of hot water and filtered off with suction. The dyestufi paste thus obtained is dissolved in 1,000 parts by volume of hot water with the addition of caustic soda solution, filtered off and an ammoniacal solution of 19 parts by weight of crystalline cobalt chloride is added drop by drop to the filtrate while stirring at 9095 C. After the metallization is complete, the product is worked up as described in Example 1. The cobalt complex of the dyestufi of the formula is obtained; it represents a black-brown powder which dissolves in hot water with a grey-brown color and dyes wool from a neutral bath in level black brown shades of very good fastness properties.

If instead of the above mentioned coupling component a corresponding quantity of 2-phcnyl-5-amino-6-metl1ylbenztriazole is used, a dyestuft of similar properties isobtained.

Example 3 22 parts by weight of 1amino-2-hydroxy-4-nitro-benzene are diazotized in 150 parts by volume of water and parts by volume of concentrated hydrochloric acid with 10 parts by weight of sodium nitrite in 30 parts by volume of water. The suspension of the diazo compound is then combined with a suspension of 30 parts by weight of 2-(3'-sulfonamido-phenyl)-5-amino-benztriazole in 200 parts by volume of water, and 20 parts by weight of crystalline sodium acetate are added thereto in small portions. After the coupling is complete, the mixture is heated to 60-70 C., the dyestuit is filtered off and dried. This is stirred into 400 parts by volume of formamide, a concentrated aqueous solution of chromium formate containing 6.2 parts by weight of chromium oxide is added to the mixture which is stirred at 120130 C. for about 3 hours until the chroming is finished. The mixture is poured into 1,500 parts by volume of a sturated common salt solution and the separated dyestuif is then filtered oil. It is dissolved in 1,000 parts by volume of hot water with the addition of causticsoda solution, the solution is filtered off and the dyestufiis precipitated by adding common salt. The filtered and dried chromium complex of the dyestufl corresponding to the formula OH HzN N V N BOQNHI a is a dark powder which dissolves in hot water with olive-green color and dyes wool from neutral bath in bluish green shades of very good fastness properties.

The cobalt complex of the same dyestuff dyes wool in yellowish olive shades of similar properties.

Example 4 :.NH: N N

is separated by the addition of common salt, filtered off and dried. It forms a dark powder which dyes wool from a neutral bath in bluish olive shades of very good fastness to wetting and to light.

Example 5 54 parts by weight of the dyestuff from diazotized 1- amino-Z-hydroxybenzene and 2-(3'-sulfonamido-phenyl- S-amino-benztriazole are dissolved in 1,000 parts by volume of water with the addition of caustic soda solution and at -95 C. there is added drop by drop an ammoniacal solution of 19 parts by weight of crystalline cobalt chloride. After the metallisation is complete, the cobalt complex of the dyestufi corresponding to the formula is separated with the addition of common salt, filtered off and dried. A dark brown powder is obtained which dissolves in hot' water with a brown color and which dyes wool from a neutral bath in level olive-tinted brown shades ofv very good fastness to. wetting and light.

Example 6 60 parts by weight of the dyestufi from diazotized 1- amino 2,5 dimethoxybenzene and 2 (3' sulfamidophenyl)-5-amino-benztriazole are stirred into 500 parts by volume of formamide, 19 parts by weight of crystalline cobalt chloride and parts by weight of crystalline sodium acetate are added thereto, and the mixture is stirred at 120-125 C. for 4 hours until the metallisation is complete. The mixture is then poured into 1,500 parts by volume of a saturated solution of common salt, the separated dyestufi is filtered off and washed. The dyestuff paste thus obtained is stirred into 500 parts by volume of water and parts by volume of caustic soda solution, filtered ed with suction and dried. The formed cobalt complex of the dyestutt having the formula CHa N-N SO2.NH

is a dark brown powder which dyes wool from a neutral bath in level olive-tinted grey shades of very good fast- The benztriazole-dyestufi intermediates are obtainable e.g. as follows:

226 parts by Weight of the azo dyestuff obtained from diazotized aniline and 2,4-diamino-toluene in form of a wet paste are stirred in an autoclave with a solution of 625 parts by weight of crystalline copper sulfate in 1500 parts by volume of percent ammonia and 3,000 parts by volume of water Within 4 hours at 120-125 After the mixture is cooled the formed crystalline product is filtered with suction washed free from copper and dried. 2-phenyl-S-amino-6-methylbenztriazole is obtained in almost quantitative yield. After recrystallized in acetone the compound has a melting point of 218219 C.

In analogous manner the following dyestufi intermediates can be prepared: 2-pheny1-5-amino-6-methoxybenztriazole, M. P. 186-187 C. 2-phenyl-5-amino-6-nitrobenztriazole, M. P. 217218 C. 2-(3-sulfamidophenyl)- S-arninobenztriazole, M. P. 288290 C.

I claim: 1. A dyestutf selected from the group consisting of 5 chromium complexes and cobalt complexes of a monoazo dyestufi corresponding to the general formula:

OH HQN I I R2 wherein R R and R stand for radicals selected from 20 the group consisting of hydrogen and non-ionic substitucuts.

2. A cobalt complex of the monoazo dyestufi corresponding to the formula:

3. A cobalt complex of the monoazo dyestufi corresponding to the formula:

4. A cobalt complex of the monoazo dyestufi corresponding to the formula:

OTHER REFERENCES Synthetic Dyes, Venkataraman, vol. 1, 1952, pages 540- 

1. A DYESTUFF SELECTED FROM THE GROUP CONSISTING OF CHROMIUM COMPLEXES AND COBALT COMPLEXES OF A MONOAZO DYESTUFF CORRESPONDING TO THE GENERAL FORMULA: 